* BOJ to increase buying of ETFs
* But keeps money base target unchanged at Y80 trln
* Yen jumps on disappointment over lack of aggressive easing
SINGAPORE, July 29 (Reuters) - The safe-haven yen jumped against the dollar on Friday after the Bank of Japan's monetary policy easing disappointed investors who had been hoping for more radical stimulus measures.
The dollar last traded at 103.35 yen, down 1.8 percent on the day. It initially rose to 105.75 yen right after the BOJ's announcement but later tumbled to as low as 102.705 yen.
"There's (dollar/yen) selling on the back of disappointment. Other than ETFs (exchange-traded funds), they didn't announce anything," said Satoshi Okagawa, senior global markets analyst for Sumitomo Mitsui Banking Corporation in Singapore.
The BOJ announced a modest increase in purchases of ETFs, but maintained its base money target at 80 trillion yen ($775 billion) as well as the pace of purchases for other assets including Japanese government bonds.
The BOJ also kept negative interest rates unchanged at minus 0.1 percent.
The euro slid 1.7 percent to 114.63 yen. (Reporting by Masayuki Kitano; Editing by Sam Holmes)